Natural Variable Equations and Partial Derivatives

Now that we have defined all independent energy quantities in terms ofp, V, T, and S, we summarize them in terms of their natural variables  

These equations are important because when the behaviors of these energies on their natural variables are known, all thermodynamic properties of the system can be determined. 

For example, consider the internal energy, U. Its natural variables are S and V that is, the internal energy is a function of S and V  

As discussed in the last chapter, the overall change in U, dU, can be separated into a component that varies with S and a component that varies with V. The variation of U with respect to S only (that is, Vis kept constant) is represented as dU/dS)y, the 

Unless otherwise noted, all art on this page is Cengage Learning 2014. 

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